In door or closure openings it may be desirable to automatically release locks having latch bolts or guarded latch bolts from their engagement in the door frame. Latch bolts are carried by a closure such as a door and are received in a strike which is mounted in a recess in a door frame. Guarded latch bolts are comprised of two elements: a latch bolt and a dead latch or latch guard. The dead latch is located directly adjacent the latch bolt and follows the latch bolt as the door or closure swings into its frame or leads the latch bolt when the door or closure swings out of its frame upon opening. The dead latch provides added security against unauthorized entry by use of devices inserted between the frame and the door or closure to depress and thus release the latch bolt.
Electric strikes that automatically release latch bolts may allow the latch bolt to ramp out of the door frame (see U.S. Pat. No. 4,626,010) or incorporate components that pivot away from the latch bolt allowing the bolt to exit the doorframe (see U.S. Pat. No. 5,934,720). Given the nature of the design of a guarded or dead latch bolt, electric strikes that ramp out a latch bolt with the dead latch can only do so if the dead latch component is first allowed to extend into a released or unlock state prior to the latch bolt being ramped out of the doorframe. Once extended to the unlocked state, the dead latch is depressed by the retracting latch bolt. Therefore it is necessary to have ramps on both sides of the dead latch to force retraction of the dead latch by ramping the latch bolt back into the door.
Normal electric strikes of the type that ramp the latch bolt back into the door or closure do not provide allowance for vertical adjustment to align the strike with the centerline of the latch bolt contained in the door. A problem occurs when a door or closure does not properly align with the doorframe causing the misalignment of the door/dead latch with the electric strike resulting in an ineffective or an inoperative strike locking system.
The present invention allows the installer of the strike to achieve vertical alignment of the strike center to the latch bolt and dead latch by a simple adjustment mechanism. The addition of dual ramps (on the strike plate and in the housing) facilitate a smooth and rapid egress of the latch from the strike during the unlocking operation of the strike. Vertical adjustability is achieved by an electric strike body having a housing faceplate, keeper and associated components common to an electric strike and further including a slotted ramp which is adjustable along the strike body and securable at a selected position. The term “vertical adjustability” is used as most enclosures such as doors are vertically mounted. However, it will be apparent that the adjustability features of the invention are applicable to installations in which the closure is non-vertical.